Granted Patent
Utility
US 6,358,421 · App. 09/551,588
Method for countercurrent regeneration of an ion exchange resin bed
Inventors:
John Newenhizen, Gene Wayman
Patented Case
View Patent ↗
Granted: Mar 19, 2002
Filed: Apr 18, 2000
Inventors
John Newenhizen
Gene Wayman
Assignee (at issue)
United States Filter Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.